Aygun Sunar 10 7 14

Semra Aygun-Sunar, PhD!!

[email protected][email protected]!

!

Cell Structure !& !

Tumor Microenvironment

RPN-530 Oncology for Scientist-I October 7, 2014

mailto:[email protected]

mailto:[email protected]

2RPN-530 Oncology for Scientist-ICell Structure & Tumor Microenvironment

Book!• Chapter 13: “The Biology of Cancer” (2nd Edition).

Robert Weinberg, Garland Science, 2013!!• “Molecular Biology of the Cell” (5th Edition). Bruce Alberts,

Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts, Peter Walter; 2008!!

Review!• Hanahan & Weinberg, Hallmarks of Cancer: the next

generation. Cell. 2011. 144: 646-674!

Reading

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Overview of this lecture• Cells & cell theory!• Structure and function of specific cell components!• Cancer cells!• Studying of cells and cellular compartments!• Communication of cells with the tumor microenvironment!! !

RPN-530 Oncology for Scientist-ICell Structure & Tumor Microenvironment

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Cell“is the functional and smallest unit in every organism ”

• All living organisms are composed of cell(s). !• Cells are the essential unit of structure and function in organisms !• Cells are produced through the division of pre-existing cells (mitosis)

Main principles of the cell theory


• The cell was first discovered by Robert Hooke (in 1665).!• The cell theory was developed by Matthias J. Schleiden, Theodor Schwann and Rudolph Virchow

(Ref: The Molecular Probes® Handbook-11th Edition, 2010, Invitrogen)!

Prokaryotic cell vs Eukaryotic cell

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Types of Cells

Prokaryotes: Archae and bacteria!• do not have nucleus, !• do not have membrane-bound

organelle, !• have cytoskeleton,!• have circular-shaped DNA.


Eukaryotes: Protists, fungi, plants, and animal (including human) !!

• contain various membrane-bound organelles,!

• have cytoskeleton, !• have chromatin and chromosome.

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Plasma membrane (or cell membrane)

• Fluid Mosaic Model!• Phospholipid bilayer (Hydrophilic polar heads face outside and hydrofobic nonpolar tails face each other)!• Contains integral (embedded in the membrane) and peripheral proteins (found on the inner membrane surface)

➢ Structure


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Plasma membrane➢Function• Separates cell contents from environment!• Serves as a diffusion barrier !! Regulation of transport by Passive transport includes ! Diffusion (“Osmosis” and “Dialysis”) or Active transport!• Detection of signals!• Cell-cell communication !• Cell identity!• Helps in cell movement


The major intracellular compartments of cell: “Organelles”

RPN-530 Oncology for Scientist-ICell Structure & Tumor Microenvironment 8

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Animal Cell Organelles Nucleus


➢ Structure I. Nuclear envelope!* Composed of inner !and outer membrane !separated by !perinuclear space!* Has nuclear pores !which connect with ER! II. Nucleoplasm !* Fluid of the nucleus! III. Nucleolus !* Not separated by

membrane!* is area of formation of

ribosomal RNA, !* is area of condensed

DNA and chromatin

DNA is tightly packaged up into nucleus!

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Animal Cell OrganellesNucleus

➢ Function


* Storage of genetic material (DNA)! * Production of messenger RNA and ribosomes that needed for protein synthesis.* Storage of proteins and RNA in the nucleolus.! * During the cell division, chromatins are arranged into chromosomes in the nucleus. * Function in selective transportation of regulatory factors and energy molecules through nuclear pores.

“contains the genetic information of the cell”

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Mitochondria

Animal Cell Organelles

“ Energy producing organelle”


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Mitochondria ➢ Structure

• Surrounded by 2 membranes:!- smooth outer membrane (permeable)!- folded inner membrane (impermeable) with layers called “cristae”!!• Contain two internal compartments:! - mitochondrial matrix is within the inner membrane (contain ribosomes mitochondrial DNA (mtDNA) and enyzmes)! - intermembrane space is located between the two membranes

The structure of mitochondria.!Ref:microbewiki.kenyon.edu/index.php/Mitochondria



mtDNA: !• inherited from mother!• not protected by histones

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MitochondriaAnimal Cell Organelles


Function: Oxidative phosphorylation”--ATP synthesis

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Ref: Murphy MP. Biochem J, 2009

Function: Reactive Oxygen Species (ROS)/ Free radical generation

http://www.ncbi.nlm.nih.gov/pubmed?term=Murphy%20MP%5bAuthor%5d&cauthor=true&cauthor_uid=19061483

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Ref: http://www.reading.ac.uk/nitricoxide/intro/apoptosis/mito.htm

Apaf-1: Apoptotic protease activating factor 1

Function: Regulation of apoptotic death and cell growth

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Endoplasmic reticulum (ER)

➢ Structure“cell’s internal membrane system”

• Cisternae (sac-like structures) !• Cisternal space (or lumen)!• ER membrane is continuous with nuclear envelope

➢ Types of ER!• Smooth-type (SER) : !•Ribosome-free!•Contains enzyme for lipid biosynthesis!•Involved in attachment of receptors on cell membrane proteins!• Rough-type (RER) : !•Ribosomes embedded in surface!•Involved in protein synthesis



Cisternae

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Endoplasmic reticulum (ER)➢Function



• Protein folding, modification and secretion!• Cellular protein quality control by extracting and degrading unfolded proteins (known as a ER-associated protein degradation-ERAD)!• Lipid and sterol biosynthesis!• Storage of calcium ions in the ER lumen and their regulated release into the cytosol (calcium homeostasis)!• Detoxification of drugs!• Core oligosaccharide biosynthesis!• Apoptosis!


Major responses to ER stress

http://www.pdbj.org/eprots/index_en.cgi?PDB%3A2RIO


Golgi ApparatusAnimal Cell Organelles

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➢ Structure• is made up numerous group of flat membranes called cisternea forming a sac!Cisternea: !* a complex network of tubules and vesicles are located at the edges of cisternea!•help proteins and cytoplasmic components travel between different parts of the cell!!• has three regions:!--- Cis face (near to ER) !Receive transport vesicles from ER --- Trans face (far away from ER)!Packages the material in vesicles and send outside of Golgi !--- Golgi stack (between these two region)!Main processing area


➢Function!

• Receives, sorts, modifies, packs and ships the proteins!• Produce membrane packages called vesicles !• Protects cells from apoptosis

Golgi ApparatusAnimal Cell Organelles

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Lysosomes



➢ Structure • are membrane enclosed vesicles (spherical bodies about 50-70 nm in diameter)!• arise from the golgi apparatus!• are found in all animal cells such as white blood cells. !• contain hydrolytic enzymes that digest & destroy macromolecules!• two types of lysosomes: !--- Peroxisomes: catalases & oxidases!--- Proteosomes: proteases- cathepsin!

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Lysosomes-“suicide bags” and “recycling”



➢ Function!•Destroy invading bacteria or viruses (Phagocytosis)!•Degrade older or damaged organelles (Autophagy) !•Degrade macromolecules (Endocytosis)

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Cytoskeleton“the movers and shapers in the cell”


is found underlying the cell membrane in the cytoplasm

* occur in every cell!* composed of polymerased actin proteins!* interact specifically with myosin helical polymers made of actin flexible, organized into 2D networks and 3D gels!* function in cell movement and cellular contraction

Microfilament structure and assembly!http://micro.magnet.fsu.edu/cells/microfilaments/microfilaments.html

I. Actin filaments (or Microfilament)Major Structures of the Cytoskeleton


* composed of polymerased alpha and beta-tubulin!* rigid, long, straight, holo tupe!* length: 200 nm-25 µm!* are used for centrioles!•structural support of Cilia and Flagella !•Involved in the movement of the materials within the cells

Microtubule helical structure!http://micro.magnet.fsu.edu/cells/microfilaments/microfilaments.html

II. MicrotubulesMajor Structures of the Cytoskeleton

Intermediate filament structure!http://micro.magnet.fsu.edu/cells/microfilaments/microfilaments.html

III. Intermediate filaments * occur only in animal cells!* composed of polymerased keratin proteins!* rope-like structure!* size: 8 -12 nm !* provide structural stability


Cytoskeleton

http://ccaoscience.wordpress.com/notes/protein-structures-within-the-cell/

Function!* Cell shape,!* Cell polarity !* Cell movement:!-muscle contraction via actin filaments and myosin proteins!-Flagella!-Cilia!* Cell cycle: !Cell division and chromosomal separation by actin and tubulin cytoskeletal structures!* Cell adhesion!* Phagocytosis (by actin filaments)!* Wound healing

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Extracellular matrix (ECM)


is the defining feature of connective tissue in animals

• is made up of Adhesive glycoproteins (fibronectin and laminin), Structural proteins (collagen and elastin) and Polysaccharides (glycosaminoglycans, proteoglycans) !

• includes the interstitial matrix and basement membrane!

• consisting of various cell types (i.e. fibroblasts, epithelial cells) and secreted proteins (cytokines)

Epithelial cells

Basement membrane!

Endothelium lining!the capillary Connective tissue with!Interstitial matrix

Fibroblasts http://en.wikipedia.org/wiki/!Extracellular_matrix

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• Cell shape,!• Cell attachment, !• Adhesion,!• Migration (example: wound healing),!• Cell proliferation, !• Polarity,!• Differentiation, !• Survival & apoptosis, !• Motility,!• Management of growth factors,!• Embryonic development.

➢ Function

Extracellular matrix (ECM)



Mesenchymal cells

• are fairly uniform small spindle-shaped cells,!• do not make mature cell-cell contacts, and can invade through the ECM,!• are connected to other cells within a 3D- cellular network,!• bipolar !• express markers such as N-cadherin, Twist, snail, fibronectin!• can migrate easily

• are polygonal in shape!• h a v e t h r e e m e m b r a n e domains: apical, lateral and basal,!• have adherens junctions !• have tight junctions between apical and lateral domains,!• express cell-cell adhesion markers such as E-cadherin, !• lack of mobility.

Epithelial Cells &Apical

Basal

Lateral


Epithelial-mesenchymal transition (EMT)

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• is characterized by loss of E-cadherin, disruption of cell adhesion, and induction of cell motility and invasion to convert a mesenchymal phenotype!!• function in embryonic development, organ formation, tissue regeneration, wound healing, organ fibrosis and cancer progression and metastasis.

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Cell-cell adhesion


• are transmembrane proteins!• mediate Ca+2-dependent cell-cell adhesion!• interact in a zipper-like fashion!• stabilized by catenin complex!• are cell type specific! Several types of cadherins:! * E-cadherin (epithelial)! * P-cadherin (placental)! * N-cadherin (neuronal)

CadherinsHomotypic cel l adhesion by E-cadherin within the epithelium.

(Ref: Mohamet et al., Journal of Oncology, 2011)

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Cell-cell adhesion


• Tight junction:!- fused membranes of adjacent cells!- form a continuous belt around cells!- impermeable!- ex: intestine, kidneys, bladder, epithelium of skin• Desmosomes!- fastening adjacent cells together by connecting cell membrane to cytoskeleton proteins!- binding spots between cells with cadherins!-ex: skin, heart

• Gap junction !-Transmembrane proteins called connexons joint together to make a channel. !- allow small molecules to pass directly from cell to cell!-ex: heart muscle, animal embryos.!(in heart muscle, the flow of ions through gap junctions coordinates the contraction)!!

“intercellular junctions”

Connexons

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Protein !filaments

Tight !junction

Plasma! membrane

Plasma !membrane

Plasma! membrane

Desmosome

Gap !junction

Intracellular !spaceTight junction!proteins

Intracellular !space

Protein!channels

Intracellular !space

Intercellular !plaques

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Cell-ECM adhesionCell adhesion molecules-”Integrins”

The regulation of the extracellular binding activity of a cell's integrins Ref: Molecular Biology of the Cell, 4th edition


• are transmembrane heterodimeric cell-surface molecules !• are receptors for ECM!• are concentrated in cell at specific zone called Focal adhesions !• are important for adhesion to ECM and transmembrane signaling!• function as a link between ECM and the actin cytoskeleton!• are important for cell growth

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Tumor typesBening (non-cancerous) tumor vs malignant (cancerous) tumor


Cancer classifications!!

Based on the location or origin of the malignant tumor

Carcinoma!Malignant tumors !of epithelial cells

Sarcoma!Malignant tumors !of supporting tissue!(non-epithelial tumors: !mesenchymal origin)!

Lymphoma!Malignant tumors !of lymphocytes!

Leukemia !Malignant tumors !of blood cells


Solid tumor Non-solid tumor

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Normal Cells vs Cancer Cells


Microscopic appearance of !cancer cells Mammary gland

Mammary carcinoma

http://www.hindawi.com/journals/ijol/2011/187623/fig1/

http://www.gfmer.ch/selected_images_v2/detail_list.php?cat1=2&cat2=8&cat3=0&cat4=3&stype=n


• Uncontrolled cellular proliferation!• Unbalanced cell division!• Loss of apoptosis!• Loss of special function (abnormal organelles and cell components and high rate of differentiation) !• Abnormal vessel wall structure!• Tissue invasion & metastasis!• Tumor-associated angiogenesis!• High glycolytic rate!• Hypoxia!

Common characteristics of cancer cells

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Nuclear structure in cancer cellsPerinucleolar !

compartmentNuclear !lamina

heterochromatin

Nucleoli

NMP

PML

Nuclear !matrix

Normal Cancer

PML: Promyelocytic leukaemia!!NMP: nuclear matrix proteins


• Single and small nucleus & nucleolus!• Fine chromatin granules in the nucleus!• Clear nuclein stain!• The smooth nuclear boarder!• Stain artifact in one cell where another small white blood cell overlaps.

• Multiple and large nucleolus & nuclei!• Large chromatin clumps in the nucleus!• The dark staining of the nucleus and!irregular nuclear boarder. !• Nuclei can become irregular and begin to fold !• PML bodies can mislocalized.!• Specific NMPs are absent!• Perinuclear compartment is present

(Ref: Zink et al., Nature reviews, 2004)!

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Mitochondria in cancer cells• mtDNA mutations inhibit oxidative phosphorylation: Increase ROS level and tumor cell proliferation


Apoptosis-resistant mitochondria and cancer

Ref: Indran et al., BBA, 2011mitochondrial membrane permeabilization (MMP) permeability transition pore complex (PTPC) HKII: hexokinase II


Ref: Wang et al., Am J Transl Res, 2010http://www.hindawi.com/isrn/cell.biology/2013/256404/fig1/

UPR & ER stress in cancer cells

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Lysosome alterations & Autophagy in cancer cells

Lysosomes in normal versus cancer cells. Visualization of the lysosomal compartment (using lysosome-associated membrane protein 1) monoclonal!antibodies, red) and the actin cytoskeleton (using anti-β-actin monoclonal antibodies, green) in murine embryonic fibroblasts. !Note the perinuclear and peripheral localization of lysosomes in control and transformed cells, respectively. !Ref: Kroemer and Jäättelä nature Reviews, 2005, 5: 886-897

Normal CancerDefects in lysosome increase expression and altered trafficking of lysosomal enzymes participates in tissue invasion, angiogenesis and lysosomal death pathway.

Autophagy act as both a “tumor suppressor” by preventing the accumulation of damaged proteins and organelles and as a “mechanism of cell survival” that can promote the growth of established tumors.



Plasma membrane structure in cancer cells

Changes in the plasma membrane fluidity of tumor cells may affect antigens and receptors as well as the cancer cell motility and capacity to infiltrate the basement membrane and the deformability potential of metastatic cells. !

EMT in Tumor Progression

Progression


Cytoskeletons in the cancer cells


Actin cytoskeleton in the invasion/ metastatic process

!Vignjevic and Montagnac, Seminars in Cancer Biology, 2008!

http://www.sciencedirect.com/science/article/pii/S1044579X07000715

http://www.sciencedirect.com/science/article/pii/S1044579X07000715

Integrins and cadherins in the cancer cells


Diagrammatic representation of the vascular system. A. Normal tissue. B. Solid tumor. Red represents well-oxygenated arterial blood, blue represents poorly oxygenated venous blood, and green represents lymphatic vessels. (Ref: Tredan et al., JNCI, 2007, 99:1441-1454)

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Blood vessels & flow in cancer cells


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How are the cells studied?


• Microscopy analysis: Light microscopy, Electron microscopy!! ! Fluorescence microscopy, Confocal microscopy!• Immunohistochemistry!• Flow cytometry analysis!

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4. Differential interference !contrast microscopy!(DIC or Nomarski)

1. Bright field!microscopy

➢ Types of light microscopes

2. Dark-field!microscopy !

3. Phase-contrast!microscopyAlter light waves !to enhance the view of specimen

The same fibroblast cell in culture shown using different types of light microcopies. !Ref: “Molecular Biology of The Cell”, 5th edition. Alberts et al., 2008. Chapter 9, p.584

Passes light !directly through specimen

Light scattered !by specimen Give specimens a 3D

appearance

• uses visible light (ranges from 0.4 µm (for violet) to 0.7 µm (for deep red) that transmitted through or reflected from specimen!• can view living cell to see their compartments!• gives 1,000X magnification


Light microscopy

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• uses beam of highly energetic electron to illuminate the specimen!• has high magnification and high resolution

Electron microscopy

! Transmission Electron Microscopy (TEM)!• uses the electrons that pass through specimen!• is used for analyzing sections !• shows only structure of cell !• gives a 2D views!• gives 1,000-500,000X magnification!! Scanning Electron Microscopy (SEM)!• uses the electrons reflected from a specimen!• is used for analyzing surface of the specimen!• shows defined organelles inside cell!• gives a 3D views !• gives 10-300,000X magnification

➢ Types of electron microscopes

Cilia lining the trachea under TEM and SEM!http://www.med.nus.edu.sg/ant/histonet/tacsem/tac20.sem.gif

TEM vs SEM

T!E!M

S!E!M


cells must be dead and specimen require specifically preparations: can be cut/sectioned or coated in gold metal


Auto-Fluorescence!• is the natural emission of light by biological structures

(such as mitochondria and lysosomes) when they have absorbed light, and is used to distinguish the light originating from artificially added fluorescent markers (fluorophores)!

• Autofluorescent molecules: NAD(P)H, flavins, collagen, elastin and chlorophyl

Fluorescence!• occurs when a molecule absorbs light at a shorter wavelength

(Excitation), and then emits light at a longer wavelength (Emission) !

• has many practical applications, including fluorescence microscopy, fluorescence spectroscopy, fluorescent labeling or dyes


Fluorescence probes-Fluorochromes

Specimens labeled with Fluorescent protein (such as Green fluorescent protein-GFP) or Fluorescent probes are used to study the organization and function of living organism.

Stably transfected human cervix carcinoma HeLa cells expressing GFP http://www.evrogen.com/products/TurboGFP/TurboGFP_Detailed_description.shtml

•Ex: Peak excitation wavelength (nm) !•Em: Peak emission wavelength (nm)

Probe Ex (nm) Em (nm)FITC (Fluorescein) 495 519R-Phycoerythrin (PE) 480;565 578Alexa Fluor 610 610 629Hoechst 33342 343 483DAPI 345 455

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Fluorescence microscopy


• exposes specimen to ultraviolet, violet, or blue light!• excites and detects Fluorescent materials!

Epithelial cells stained with DAPI (blue) and two antibodies (green and red) via immunofluorescence

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Confocal microscopy


• is used with Fluorescent specimens !• has two parts: optical sectioning and 3D-reconstraction!-- takes a series of images to record!-- computer generate a movie showing the 3D rotation of the image!!!!!

Confocal fluorescence microscopy of focal adhesion and actin cytoskeleton in COS-7 cells revealed with triple labeling using TRITC-conjugated phalloidin, anti-Vinculin and DAPI. http://www.millipore.com/antibodies/flx4/cell_structure&tab1=5&tab2=3#tab2=3:tab1=5

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Wide-field epifluoresence vs Confocal microscopy


• gives nice images that have in-focus light!• does performs optical sectioning of thick samples,!• is ability to control depth of field, !• provides 3D-image reconstruction,!• detects very weak fluorescent signals,!• generates high-resolution images,!• has more color possibilities.

• gives very nice images that have both in-focus and out-focus light !•works with very thin specimens or when a thick specimen is cut into sections.

microscopy

http://www.itg.uiuc.edu/technology/atlas/

microscopy/confocal.htm


Immunohistochemistry (IHC)• is a technique that combines histological, immunological and biochemical techniques.!• shows specific antigens in tissues by the use of markers that are either fluorescent dyes or enzymes (such as horseradish peroxidase)!!This technique can be used !• to identify different types of cells in a tissue!• to visualize the distribution and localization of specific cellular components within a cell or tissue!• to locate particular cells and proteins!• to identify cellular events – e.g.apoptosis!

The technique comprises two phases: !1. Slide preparation: Specimen fixation, tissue processing (embedding,

sectioning & mounting, epitope (antigen) recovery, blocking, immune detection)!2. Sample visualization


Flow cytometry analysis!• is a technique in which cells suspended in a fluid flow !• uses the principle of light scattering, light excitation, and emission of flurochoromes!• is used for counting and analyzing the physical characteristics of individual cells!!This technique can be used !• to measure the amount of DNA in cells. !• to detect populations of cells that have abnormal amounts of DNA (important for clinical study)!• to quantify the proteins in the cells (such as cytoskeletal proteins)!!


Non-small cell lung cancer (H1299)

Immunohistochemistry !analysis

Ref: Leung EL-H, Fiscus RR, Tung JW, Tin VP-C, et al. (2010) Non-Small Cell Lung Cancer Cells Expressing CD44 Are Enriched for Stem Cell-Like Properties. PLoS ONE 5(11): e14062. doi:10.1371/journal.pone.0014062

SSC: side scatter

Surface marker expression

Flow cytometry analysis

FITC: fluorescein isothiocyanate


Tumors as 'wounds that do not heal'

Normal skin tissue Invasive carcinoma

Normal stroma vs tumor microenvironment


(Zhang and Liu, Pharmacology and Therapeutics 137(2), 2013


• Neoplastic cells: i.e. cancer stem cells, cancer associated fibroblast, !• Infiltrating cells: i.e. lymphocyte, macrophage,!• Resident cells: i.e. fibroblasts, endothelial cells, !• Secreted soluble factors ! Cytokines (i.e. CXCR-4 and CXCL-12, TNF-α), ! Matrix-altering enzymes” (i.e. matrix metalloproteinases (MMPs)) Growth factors !VEGF: Vascular endothelial growth factor, !FDG: Fibroblast growth factors !PDGF: The platelet derived growth factor !TGF-β: Transforming growth factor beta !• The extracellular matrix !• Hypoxia (low oxygen levels)!• Acidic conditions (low pH level)!• Hypoglycemia (low glucose level) !• Massive cell death !• Abnormal properties of surrounding cells

The tumor microenvironment

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Cancer stem cells


• are principal cellular component of connective tissue!• synthesize ECM and collagen!• are involved in the production & remodeling of the ECM !• provide potentially oncogenic signals such as TGF-β and hepatocyte growth factor (HGF) to resident epithelia !• stimulate cancer-cell proliferation and invasion by secreting growth factors such as TGF-β and stromal-cell-derived factor 1 (SDF1).

Fibroblasts

NIH/3T3 Fibroblasts in cell culture (Ref: http://en.wikipedia.org/wiki/Fibroblast)!


Tumor Associated Fibroblasts

Tumor associated fibroblastFibroblast

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Endothelial cells & Pericytes


Endothelial–pericyte interactions in microvessels

Ref: Armulik et al., Circulation Research, 2005

Pericytes are adjacent to endothelial cells and embedded within the vascular basement membrane of blood microvessels. !They participate in the construction of the tumor-associated vasculature

Pericytes - Endothelial cells signaling network can contribute to tumor development and metastasisTumor-associated endothelial cells!

Function in tumor development, progression and metastasis formation and !Angiogenesis/ lymphangiogenesis)

EC

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Immune inflammatory cells


Many tumor-associated immune cells such as macrophages, dendritic cells, and cytotoxic T cells may either promote tumor growth and progression or protect the cancer cell from apoptosis

Macrophages !• are white blood cells !• are crucial member of tumor stromal cells. !• are phagocyte of cell debris and pathogens !• function in wound healing, inflammatory !response

Tumor associated macrophages!• induce tumor growth,!• promote angiogenesis,!• enhancement of tumor cell migration and invasion, !• promote metastasis

http://legacy.owensboro.kctcs.edu/gcaplan/anat/histology/api%20histo%20connective.htm

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Adipocytes• are in mammary gland and bone marrow!• act as a energy source for the normal and cancer cells!• secrete hormons, growth factors, MMPs and specific cytokines (i.e. adipokines, adiponectin, resistin, visfatin)!• primarily constitute adipose tissue!• are involved in tumor progression


Section of tumor (mauve) in the presence of adipocytes (white discs). The arrows indicate adipocytes modified by the tumor. !(Credit: Copyright G. Escourrou)

Metalloproteinases (MMPs)


• are metal-dependent endopeptidases !• are produced by stromal cells rather than by tumor cells in many solid tumors

Ref: Roy et al., JCO, 2009

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•

B


Hypoxia in solid tumorImbalance between oxygen supply and oxygen consumption in tumors

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A

Hypoxia-induced angiogenesis

Molecular mechanisms of tumor-associated angiogenesis. (Ref: Simpson-Haidaris et al., PPAR Research, 2010) !


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A


B

Tumor-associated angiogenesis is sustained through stromal microenvironment crosstalk. (Ref: Simpson-Haidaris et al., PPAR Research, 2010)

Tumor-associated angiogenesis in tumor microenvironment

Hypoxia-induced EMT in tumor microenvironment

Various factors that induce cancer cell EMT in tumor microenvironment. (Ref: Jing et al., Cell & Bioscience 2011, 1:29)


Communication of tumor cells with tumor microenvironment


Ref: Sun et al., Cancer Metastatis Rev. 2010Intravasation

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.

SDF-1 & CXCR4 in Tumor microenvironment


Ref: Orimo and Weinberg (2006)

EPCs: Endothelial progenitor cells

stromal cell derived factor-SDF-1 (CXCL12)

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(Ref: Kojima et al., PNAS 2010, 107(46): 20009–20014)


TGF-β and SDF-1 autocrine signaling in myofibroblast formation


Transforming growth factor beta (TGF-β) in cross talk


..

Ref: Sun et al., Cancer Metastatis Rev. 2010

Organ-spesific metastasis & tumor microenvironment

Hedgehog signaling

Ref: Epstein, Nature Reviews Cancer 8, 2008


Basal cell carcinomaNormal

(Smoothened) Patched domain-containing protein (The Suppresor !

of Fused)

Hedgehog signaling in tumor microenvironment

Ref: Curran & Ng, Nature 455, 2008


Sample Questions


1. Match the following!a-Metalloproteinases 1. is a part of endomembrane system!b-Mitochondria! ! 2. express alpha smooth muscle actin !c-VEGF! ! ! 3. cause extracelullar matrix degradation!d-Integrin!! ! 4. contains own DNA that is not protected by histons!e-Myofibroblasts! ! 5. stimulates angiogenesis! !f-Golgi apparatus! ! 6-helps cell-extracellular matrix adhesion!!2. Which of the following(s) is/are true?!A. Pericytes acquire an “activated” phenotype within the tumor !characterized by expression of α-SMA and increasing !proliferation and motility.!B. Adipocytes act as a energy source for the cancer cells !C. EMT is characterized by loss of integrin and disruption of !cell adhesion!!3. List the common characteristics of cancer cells

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Aygun Sunar 10 7 14